summaryrefslogtreecommitdiff
path: root/src/backend/utils/adt
AgeCommit message (Collapse)Author
2021-09-06Fix bogus timetz_zone() results for DYNTZ abbreviations.Tom Lane
timetz_zone() delivered completely wrong answers if the zone was specified by a dynamic TZ abbreviation, because it failed to account for the difference between the POSIX conventions for field values in struct pg_tm and the conventions used in PG-specific datetime code. As a stopgap fix, just adjust the tm_year and tm_mon fields to match PG conventions. This is fixed in a different way in HEAD (388e71af8) but I don't want to back-patch the change of reference point. Discussion: https://postgr.es/m/CAJ7c6TOMG8zSNEZtCn5SPe+cCk3Lfxb71ZaQwT2F4T7PJ_t=KA@mail.gmail.com
2021-08-25Improve error message about valid value for distance in phrase operator.Fujii Masao
The distance in phrase operator must be an integer value between zero and MAXENTRYPOS inclusive. But previously the error message about its valid value included the information about its upper limit but not lower limit (i.e., zero). This commit improves the error message so that it also includes the information about its lower limit. Back-patch to v9.6 where full-text phrase search was supported. Author: Kyotaro Horiguchi Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/20210819.170315.1413060634876301811.horikyota.ntt@gmail.com
2021-08-06Adjust the integer overflow tests in the numeric code.Dean Rasheed
Formerly, the numeric code tested whether an integer value of a larger type would fit in a smaller type by casting it to the smaller type and then testing if the reverse conversion produced the original value. That's perfectly fine, except that it caused a test failure on buildfarm animal castoroides, most likely due to a compiler bug. Instead, do these tests by comparing against PG_INT16/32_MIN/MAX. That matches existing code in other places, such as int84(), which is more widely tested, and so is less likely to go wrong. While at it, add regression tests covering the numeric-to-int8/4/2 conversions, and adjust the recently added tests to the style of 434ddfb79a (on the v11 branch) to make failures easier to diagnose. Per buildfarm via Tom Lane, reviewed by Tom Lane. Discussion: https://postgr.es/m/2394813.1628179479%40sss.pgh.pa.us
2021-08-06Fix wordingPeter Eisentraut
2021-08-05Fix division-by-zero error in to_char() with 'EEEE' format.Dean Rasheed
This fixes a long-standing bug when using to_char() to format a numeric value in scientific notation -- if the value's exponent is less than -NUMERIC_MAX_DISPLAY_SCALE-1 (-1001), it produced a division-by-zero error. The reason for this error was that get_str_from_var_sci() divides its input by 10^exp, which it produced using power_var_int(). However, the underflow test in power_var_int() causes it to return zero if the result scale is too small. That's not a problem for power_var_int()'s only other caller, power_var(), since that limits the rscale to 1000, but in get_str_from_var_sci() the exponent can be much smaller, requiring a much larger rscale. Fix by introducing a new function to compute 10^exp directly, with no rscale limit. This also allows 10^exp to be computed more efficiently, without any numeric multiplication, division or rounding. Discussion: https://postgr.es/m/CAEZATCWhojfH4whaqgUKBe8D5jNHB8ytzemL-PnRx+KCTyMXmg@mail.gmail.com
2021-07-31Fix corner-case errors and loss of precision in numeric_power().Dean Rasheed
This fixes a couple of related problems that arise when raising numbers to very large powers. Firstly, when raising a negative number to a very large integer power, the result should be well-defined, but the previous code would only cope if the exponent was small enough to go through power_var_int(). Otherwise it would throw an internal error, attempting to take the logarithm of a negative number. Fix this by adding suitable handling to the general case in power_var() to cope with negative bases, checking for integer powers there. Next, when raising a (positive or negative) number whose absolute value is slightly less than 1 to a very large power, the result should approach zero as the power is increased. However, in some cases, for sufficiently large powers, this would lose all precision and return 1 instead of 0. This was due to the way that the local_rscale was being calculated for the final full-precision calculation: local_rscale = rscale + (int) val - ln_dweight + 8 The first two terms on the right hand side are meant to give the number of significant digits required in the result ("val" being the estimated result weight). However, this failed to account for the fact that rscale is clipped to a maximum of NUMERIC_MAX_DISPLAY_SCALE (1000), and the result weight might be less then -1000, causing their sum to be negative, leading to a loss of precision. Fix this by forcing the number of significant digits calculated to be nonnegative. It's OK for it to be zero (when the result weight is less than -1000), since the local_rscale value then includes a few extra digits to ensure an accurate result. Finally, add additional underflow checks to exp_var() and power_var(), so that they consistently return zero for cases like this where the result is indistinguishable from zero. Some paths through this code already returned zero in such cases, but others were throwing overflow errors. Dean Rasheed, reviewed by Yugo Nagata. Discussion: http://postgr.es/m/CAEZATCW6Dvq7+3wN3tt5jLj-FyOcUgT5xNoOqce5=6Su0bCR0w@mail.gmail.com
2021-07-28Avoid using ambiguous word "non-negative" in error messages.Fujii Masao
The error messages using the word "non-negative" are confusing because it's ambiguous about whether it accepts zero or not. This commit improves those error messages by replacing it with less ambiguous word like "greater than zero" or "greater than or equal to zero". Also this commit added the note about the word "non-negative" to the error message style guide, to help writing the new error messages. When postgres_fdw option fetch_size was set to zero, previously the error message "fetch_size requires a non-negative integer value" was reported. This error message was outright buggy. Therefore back-patch to all supported versions where such buggy error message could be thrown. Reported-by: Hou Zhijie Author: Bharath Rupireddy Reviewed-by: Kyotaro Horiguchi, Fujii Masao Discussion: https://postgr.es/m/OS0PR01MB5716415335A06B489F1B3A8194569@OS0PR01MB5716.jpnprd01.prod.outlook.com
2021-07-10Fix numeric_mul() overflow due to too many digits after decimal point.Dean Rasheed
This fixes an overflow error when using the numeric * operator if the result has more than 16383 digits after the decimal point by rounding the result. Overflow errors should only occur if the result has too many digits *before* the decimal point. Discussion: https://postgr.es/m/CAEZATCUmeFWCrq2dNzZpRj5+6LfN85jYiDoqm+ucSXhb9U2TbA@mail.gmail.com
2021-07-09Add missing Int64GetDatum macro in dbsize.cDavid Rowley
I accidentally missed adding this when adjusting 55fe60938 for back patching. This adjustment was made for 9.6 to 13. 14 and master are not affected. Discussion: https://postgr.es/m/CAApHDvp=twCsGAGQG=A=cqOaj4mpknPBW-EZB-sd+5ZS5gCTtA@mail.gmail.com
2021-07-09Fix incorrect return value in pg_size_pretty(bigint)David Rowley
Due to how pg_size_pretty(bigint) was implemented, it's possible that when given a negative number of bytes that the returning value would not match the equivalent positive return value when given the equivalent positive number of bytes. This was due to two separate issues. 1. The function used bit shifting to convert the number of bytes into larger units. The rounding performed by bit shifting is not the same as dividing. For example -3 >> 1 = -2, but -3 / 2 = -1. These two operations are only equivalent with positive numbers. 2. The half_rounded() macro rounded towards positive infinity. This meant that negative numbers rounded towards zero and positive numbers rounded away from zero. Here we fix #1 by dividing the values instead of bit shifting. We fix #2 by adjusting the half_rounded macro always to round away from zero. Additionally, adjust the pg_size_pretty(numeric) function to be more explicit that it's using division rather than bit shifting. A casual observer might have believed bit shifting was used due to a static function being named numeric_shift_right. However, that function was calculating the divisor from the number of bits and performed division. Here we make that more clear. This change is just cosmetic and does not affect the return value of the numeric version of the function. Here we also add a set of regression tests both versions of pg_size_pretty() which test the values directly before and after the function switches to the next unit. This bug was introduced in 8a1fab36a. Prior to that negative values were always displayed in bytes. Author: Dean Rasheed, David Rowley Discussion: https://postgr.es/m/CAEZATCXnNW4HsmZnxhfezR5FuiGgp+mkY4AzcL5eRGO4fuadWg@mail.gmail.com Backpatch-through: 9.6, where the bug was introduced.
2021-06-22Back-patch "Tolerate version lookup failure for old style Windows locale names."Thomas Munro
If users provide old style pre-standardized Windows locale names in a CREATE COLLATION command, the OS is unable to provide version information. Continue without capturing version information, rather than exposing an OS error. This was originally done in commit 9f12a3b9 for 14 only, to support future features that might encounter old style names from initdb's default. It wasn't done in 13 because I didn't consider that users might actually want to use the old format explicitly (something we should consider blocking in a future release with a better error message, but that's not a policy we've decided on yet). Back-patch to 13, based on the field complaint in pgsql-bugs #17058. Reported-by: Yasushi Yamashita <developer@yamashi-ta.jp> Discussion: https://postgr.es/m/17058-b49f5793c912c5aa%40postgresql.org
2021-06-12Ensure pg_filenode_relation(0, 0) returns NULL.Tom Lane
Previously, a zero value for the relfilenode resulted in a confusing error message about "unexpected duplicate". This function returns NULL for other invalid relfilenode values, so zero should be treated likewise. It's been like this all along, so back-patch to all supported branches. Justin Pryzby Discussion: https://postgr.es/m/20210612023324.GT16435@telsasoft.com
2021-06-01Reject SELECT ... GROUP BY GROUPING SETS (()) FOR UPDATE.Tom Lane
This case should be disallowed, just as FOR UPDATE with a plain GROUP BY is disallowed; FOR UPDATE only makes sense when each row of the query result can be identified with a single table row. However, we missed teaching CheckSelectLocking() to check groupingSets as well as groupClause, so that it would allow degenerate grouping sets. That resulted in a bad plan and a null-pointer dereference in the executor. Looking around for other instances of the same bug, the only one I found was in examine_simple_variable(). That'd just lead to silly estimates, but it should be fixed too. Per private report from Yaoguang Chen. Back-patch to all supported branches.
2021-05-10Prevent integer overflows in array subscripting calculations.Tom Lane
While we were (mostly) careful about ensuring that the dimensions of arrays aren't large enough to cause integer overflow, the lower bound values were generally not checked. This allows situations where lower_bound + dimension overflows an integer. It seems that that's harmless so far as array reading is concerned, except that array elements with subscripts notionally exceeding INT_MAX are inaccessible. However, it confuses various array-assignment logic, resulting in a potential for memory stomps. Fix by adding checks that array lower bounds aren't large enough to cause lower_bound + dimension to overflow. (Note: this results in disallowing cases where the last subscript position would be exactly INT_MAX. In principle we could probably allow that, but there's a lot of code that computes lower_bound + dimension and would need adjustment. It seems doubtful that it's worth the trouble/risk to allow it.) Somewhat independently of that, array_set_element() was careless about possible overflow when checking the subscript of a fixed-length array, creating a different route to memory stomps. Fix that too. Security: CVE-2021-32027
2021-04-12Use "-I." in directories holding Bison parsers, for Oracle compilers.Noah Misch
With the Oracle Developer Studio 12.6 compiler, #line directives alter the current source file location for purposes of #include "..." directives. Hence, a VPATH build failed with 'cannot find include file: "specscanner.c"'. With two exceptions, parser-containing directories already add "-I. -I$(srcdir)"; eliminate the exceptions. Back-patch to 9.6 (all supported versions).
2021-04-12Fix out-of-bound memory access for interval -> char conversionMichael Paquier
Using Roman numbers (via "RM" or "rm") for a conversion to calculate a number of months has never considered the case of negative numbers, where a conversion could easily cause out-of-bound memory accesses. The conversions in themselves were not completely consistent either, as specifying 12 would result in NULL, but it should mean XII. This commit reworks the conversion calculation to have a more consistent behavior: - If the number of months and years is 0, return NULL. - If the number of months is positive, return the exact month number. - If the number of months is negative, do a backward calculation, with -1 meaning December, -2 November, etc. Reported-by: Theodor Arsenij Larionov-Trichkin Author: Julien Rouhaud Discussion: https://postgr.es/m/16953-f255a18f8c51f1d5@postgresql.org backpatch-through: 9.6
2021-04-04Fix more confusion in SP-GiST.Tom Lane
spg_box_quad_leaf_consistent unconditionally returned the leaf datum as leafValue, even though in its usage for poly_ops that value is of completely the wrong type. In versions before 12, that was harmless because the core code did nothing with leafValue in non-index-only scans ... but since commit 2a6368343, if we were doing a KNN-style scan, spgNewHeapItem would unconditionally try to copy the value using the wrong datatype parameters. Said copying is a waste of time and space if we're not going to return the data, but it accidentally failed to fail until I fixed the datatype confusion in ac9099fc1. Hence, change spgNewHeapItem to not copy the datum unless we're actually going to return it later. This saves cycles and dodges the question of whether lossy opclasses are returning the right type. Also change spg_box_quad_leaf_consistent to not return data that might be of the wrong type, as insurance against somebody introducing a similar bug into the core code in future. It seems like a good idea to back-patch these two changes into v12 and v13, although I'm afraid to change spgNewHeapItem's mistaken idea of which datatype to use in those branches. Per buildfarm results from ac9099fc1. Discussion: https://postgr.es/m/3728741.1617381471@sss.pgh.pa.us
2021-03-26Fix ndistinct estimates with system attributesTomas Vondra
When estimating the number of groups using extended statistics, the code was discarding information about system attributes. This led to strange situation that SELECT 1 FROM t GROUP BY ctid; could have produced higher estimate (equal to pg_class.reltuples) than SELECT 1 FROM t GROUP BY a, b, ctid; with extended statistics on (a,b). Fixed by retaining information about the system attribute. Backpatch all the way to 10, where extended statistics were introduced. Author: Tomas Vondra Backpatch-through: 10
2021-03-18Fix function name in error hintMagnus Hagander
pg_read_file() is the function that's in core, pg_file_read() is in adminpack. But when using pg_file_read() in adminpack it calls the *C* level function pg_read_file() in core, which probably threw the original author off. But the error hint should be about the SQL function. Reported-By: Sergei Kornilov Backpatch-through: 11 Discussion: https://postgr.es/m/373021616060475@mail.yandex.ru
2021-02-16Convert tsginidx.c's GIN indexing logic to fully ternary operation.Tom Lane
Commit 2f2007fbb did this partially, but there were two remaining warts. checkcondition_gin handled some uncertain cases by setting the out-of-band recheck flag, some by returning TS_MAYBE, and some by doing both. Meanwhile, TS_execute arbitrarily converted a TS_MAYBE result to TS_YES. Thus, if checkcondition_gin chose to only return TS_MAYBE, the outcome would be TS_YES with no recheck flag, potentially resulting in wrong query outputs. The case where this'd happen is if there were GIN_MAYBE entries in the indexscan results passed to gin_tsquery_[tri]consistent, which so far as I can see would only happen if the tidbitmap used to accumulate indexscan results grew large enough to become lossy. I initially thought of fixing this by ensuring we always set the recheck flag as well as returning TS_MAYBE in uncertain cases. But that errs in the other direction, potentially forcing rechecks of rows that provably match the query (since the recheck flag remains set even if TS_execute later finds that the answer must be TS_YES). Instead, let's get rid of the out-of-band recheck flag altogether and rely on returning TS_MAYBE. This requires exporting a version of TS_execute that will actually return the full ternary result of the evaluation ... but we likely should have done that to start with. Unfortunately it doesn't seem practical to add a regression test case that covers this: the amount of data needed to cause the GIN bitmap to become lossy results in a longer runtime than I think we want to have in the tests. (I'm wondering about allowing smaller work_mem settings to ameliorate that, but it'd be a matter for a separate patch.) Per bug #16865 from Dimitri Nüscheler. Back-patch to v13 where the faulty commit came in. Discussion: https://postgr.es/m/16865-4ffdc3e682e6d75b@postgresql.org
2021-02-12Avoid divide-by-zero in regex_selectivity() with long fixed prefix.Tom Lane
Given a regex pattern with a very long fixed prefix (approaching 500 characters), the result of pow(FIXED_CHAR_SEL, fixed_prefix_len) can underflow to zero. Typically the preceding selectivity calculation would have underflowed as well, so that we compute 0/0 and get NaN. In released branches this leads to an assertion failure later on. That doesn't happen in HEAD, for reasons I've not explored yet, but it's surely still a bug. To fix, just skip the division when the pow() result is zero, so that we'll (most likely) return a zero selectivity estimate. In the edge cases where "sel" didn't yet underflow, perhaps this isn't desirable, but I'm not sure that the case is worth spending a lot of effort on. The results of regex_selectivity_sub() are barely worth the electrons they're written on anyway :-( Per report from Alexander Lakhin. Back-patch to all supported versions. Discussion: https://postgr.es/m/6de0a0c3-ada9-cd0c-3e4e-2fa9964b41e3@gmail.com
2021-01-25Fix broken ruleutils support for function TRANSFORM clauses.Tom Lane
I chanced to notice that this dumped core due to a faulty Assert. To add insult to injury, the output has been misformatted since v11. Obviously we need some regression testing here. Discussion: https://postgr.es/m/d1cc628c-3953-4209-957b-29427acc38c8@www.fastmail.com
2021-01-21Fix pull_varnos' miscomputation of relids set for a PlaceHolderVar.Tom Lane
Previously, pull_varnos() took the relids of a PlaceHolderVar as being equal to the relids in its contents, but that fails to account for the possibility that we have to postpone evaluation of the PHV due to outer joins. This could result in a malformed plan. The known cases end up triggering the "failed to assign all NestLoopParams to plan nodes" sanity check in createplan.c, but other symptoms may be possible. The right value to use is the join level we actually intend to evaluate the PHV at. We can get that from the ph_eval_at field of the associated PlaceHolderInfo. However, there are some places that call pull_varnos() before the PlaceHolderInfos have been created; in that case, fall back to the conservative assumption that the PHV will be evaluated at its syntactic level. (In principle this might result in missing some legal optimization, but I'm not aware of any cases where it's an issue in practice.) Things are also a bit ticklish for calls occurring during deconstruct_jointree(), but AFAICS the ph_eval_at fields should have reached their final values by the time we need them. The main problem in making this work is that pull_varnos() has no way to get at the PlaceHolderInfos. We can fix that easily, if a bit tediously, in HEAD by passing it the planner "root" pointer. In the back branches that'd cause an unacceptable API/ABI break for extensions, so leave the existing entry points alone and add new ones with the additional parameter. (If an old entry point is called and encounters a PHV, it'll fall back to using the syntactic level, again possibly missing some valid optimization.) Back-patch to v12. The computation is surely also wrong before that, but it appears that we cannot reach a bad plan thanks to join order restrictions imposed on the subquery that the PlaceHolderVar came from. The error only became reachable when commit 4be058fe9 allowed trivial subqueries to be collapsed out completely, eliminating their join order restrictions. Per report from Stephan Springl. Discussion: https://postgr.es/m/171041.1610849523@sss.pgh.pa.us
2021-01-05Add an explicit cast to double when using fabs().Dean Rasheed
Commit bc43b7c2c0 used fabs() directly on an int variable, which apparently requires an explicit cast on some platforms. Per buildfarm.
2021-01-05Fix numeric_power() when the exponent is INT_MIN.Dean Rasheed
In power_var_int(), the computation of the number of significant digits to use in the computation used log(Abs(exp)), which isn't safe because Abs(exp) returns INT_MIN when exp is INT_MIN. Use fabs() instead of Abs(), so that the exponent is cast to a double before the absolute value is taken. Back-patch to 9.6, where this was introduced (by 7d9a4737c2). Discussion: https://postgr.es/m/CAEZATCVd6pMkz=BrZEgBKyqqJrt2xghr=fNc8+Z=5xC6cgWrWA@mail.gmail.com
2021-01-04Fix integer-overflow corner cases in substring() functions.Tom Lane
If the substring start index and length overflow when added together, substring() misbehaved, either throwing a bogus "negative substring length" error on a case that should succeed, or failing to complain that a negative length is negative (and instead returning the whole string, in most cases). Unsurprisingly, the text, bytea, and bit variants of the function all had this issue. Rearrange the logic to ensure that negative lengths are always rejected, and add an overflow check to handle the other case. Also install similar guards into detoast_attr_slice() (nee heap_tuple_untoast_attr_slice()), since it's far from clear that no other code paths leading to that function could pass it values that would overflow. Patch by myself and Pavel Stehule, per bug #16804 from Rafi Shamim. Back-patch to v11. While these bugs are old, the common/int.h infrastructure for overflow-detecting arithmetic didn't exist before commit 4d6ad3125, and it doesn't seem like these misbehaviors are bad enough to justify developing a standalone fix for the older branches. Discussion: https://postgr.es/m/16804-f4eeeb6c11ba71d4@postgresql.org
2020-12-25Invalidate acl.c caches when pg_authid changes.Noah Misch
This makes existing sessions reflect "ALTER ROLE ... [NO]INHERIT" as quickly as they have been reflecting "GRANT role_name". Back-patch to 9.5 (all supported versions). Reviewed by Nathan Bossart. Discussion: https://postgr.es/m/20201221095028.GB3777719@rfd.leadboat.com
2020-12-21Remove "invalid concatenation of jsonb objects" error case.Tom Lane
The jsonb || jsonb operator arbitrarily rejected certain combinations of scalar and non-scalar inputs, while being willing to concatenate other combinations. This was of course quite undocumented. Rather than trying to document it, let's just remove the restriction, creating a uniform rule that unless we are handling an object-to-object concatenation, non-array inputs are converted to one-element arrays, resulting in an array-to-array concatenation. (This does not change the behavior for any case that didn't throw an error before.) Per complaint from Joel Jacobson. Back-patch to all supported branches. Discussion: https://postgr.es/m/163099.1608312033@sss.pgh.pa.us
2020-11-25Remove obsolete comment atop ri_PlanCheck.Amit Kapila
Commit 5b7ba75f7f removed the unused parameter but forgot to update the nearby comments. Author: Li Japin Backpatch-through: 13, where it was introduced Discussion: https://postgr.es/m/0E2F62A2-B2F1-4052-83AE-F0BEC8A75789@hotmail.com
2020-11-10Fix and simplify some usages of TimestampDifference().Tom Lane
Introduce TimestampDifferenceMilliseconds() to simplify callers that would rather have the difference in milliseconds, instead of the select()-oriented seconds-and-microseconds format. This gets rid of at least one integer division per call, and it eliminates some apparently-easy-to-mess-up arithmetic. Two of these call sites were in fact wrong: * pg_prewarm's autoprewarm_main() forgot to multiply the seconds by 1000, thus ending up with a delay 1000X shorter than intended. That doesn't quite make it a busy-wait, but close. * postgres_fdw's pgfdw_get_cleanup_result() thought it needed to compute microseconds not milliseconds, thus ending up with a delay 1000X longer than intended. Somebody along the way had noticed this problem but misdiagnosed the cause, and imposed an ad-hoc 60-second limit rather than fixing the units. This was relatively harmless in context, because we don't care that much about exactly how long this delay is; still, it's wrong. There are a few more callers of TimestampDifference() that don't have a direct need for seconds-and-microseconds, but can't use TimestampDifferenceMilliseconds() either because they do need microsecond precision or because they might possibly deal with intervals long enough to overflow 32-bit milliseconds. It might be worth inventing another API to improve that, but that seems outside the scope of this patch; so those callers are untouched here. Given the fact that we are fixing some bugs, and the likelihood that future patches might want to back-patch code that uses this new API, back-patch to all supported branches. Alexey Kondratov and Tom Lane Discussion: https://postgr.es/m/3b1c053a21c07c1ed5e00be3b2b855ef@postgrespro.ru
2020-11-04Enable hash partitioning of text arraysPeter Eisentraut
hash_array_extended() needs to pass PG_GET_COLLATION() to the hash function of the element type. Otherwise, the hash function of a collation-aware data type such as text will error out, since the introduction of nondeterministic collation made hash functions require a collation, too. The consequence of this is that before this change, hash partitioning using an array over text in the partition key would not work. Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/32c1fdae-95c6-5dc6-058a-a90330a3b621%40enterprisedb.com
2020-10-07Prevent internal overflows in date-vs-timestamp and related comparisons.Tom Lane
The date-vs-timestamp, date-vs-timestamptz, and timestamp-vs-timestamptz comparators all worked by promoting the first type to the second and then doing a simple same-type comparison. This works fine, except when the conversion result is out of range, in which case we throw an entirely avoidable error. The sources of such failures are (a) type date can represent dates much farther in the future than the timestamp types can; (b) timezone rotation might cause a just-in-range timestamp value to become a just-out-of-range timestamptz value. Up to now we just ignored these corner-case issues, but now we have an actual user complaint (bug #16657 from Huss EL-Sheikh), so let's do something about it. It turns out that commit 52ad1e659 already built all the necessary infrastructure to support error-free comparisons, but neglected to actually use it in the main-line code paths. Fix that, do a little bit of code style review, and remove the now-duplicate logic in jsonpath_exec.c. Back-patch to v13 where 52ad1e659 came in. We could take this back further by back-patching said infrastructure, but given the small number of complaints so far, I don't feel a great need to. Discussion: https://postgr.es/m/16657-cde2f876d8cc7971@postgresql.org
2020-09-30Fix handling of BC years in to_date/to_timestamp.Tom Lane
Previously, a conversion such as to_date('-44-02-01','YYYY-MM-DD') would result in '0045-02-01 BC', as the code attempted to interpret the negative year as BC, but failed to apply the correction needed for our internal handling of BC years. Fix the off-by-one problem. Also, arrange for the combination of a negative year and an explicit "BC" marker to cancel out and produce AD. This is how the negative-century case works, so it seems sane to do likewise. Continue to read "year 0000" as 1 BC. Oracle would throw an error, but we've accepted that case for a long time so I'm hesitant to change it in a back-patch. Per bug #16419 from Saeed Hubaishan. Back-patch to all supported branches. Dar Alathar-Yemen and Tom Lane Discussion: https://postgr.es/m/16419-d8d9db0a7553f01b@postgresql.org
2020-09-29Support for ISO 8601 in the jsonpath .datetime() methodAlexander Korotkov
The SQL standard doesn't require jsonpath .datetime() method to support the ISO 8601 format. But our to_json[b]() functions convert timestamps to text in the ISO 8601 format in the sake of compatibility with javascript. So, we add support of the ISO 8601 to the jsonpath .datetime() in the sake compatibility with to_json[b](). The standard mode of datetime parsing currently supports just template patterns and separators in the format string. In order to implement ISO 8601, we have to add support of the format string double quotes to the standard parsing mode. Discussion: https://postgr.es/m/94321be0-cc96-1a81-b6df-796f437f7c66%40postgrespro.ru Author: Nikita Glukhov, revised by me Backpatch-through: 13
2020-09-29Remove excess space from jsonpath .datetime() default format stringAlexander Korotkov
bffe1bd684 has introduced jsonpath .datetime() method, but default formats for time and timestamp contain excess space between time and timezone. This commit removes this excess space making behavior of .datetime() method standard-compliant. Discussion: https://postgr.es/m/94321be0-cc96-1a81-b6df-796f437f7c66%40postgrespro.ru Author: Nikita Glukhov Backpatch-through: 13
2020-09-28Add for_each_from, to simplify loops starting from non-first list cells.Tom Lane
We have a dozen or so places that need to iterate over all but the first cell of a List. Prior to v13 this was typically written as for_each_cell(lc, lnext(list_head(list))) Commit 1cff1b95a changed these to for_each_cell(lc, list, list_second_cell(list)) This patch introduces a new macro for_each_from() which expresses the start point as a list index, allowing these to be written as for_each_from(lc, list, 1) This is marginally more efficient, since ForEachState.i can be initialized directly instead of backing into it from a ListCell address. It also seems clearer and less typo-prone. Some of the remaining uses of for_each_cell() look like they could profitably be changed to for_each_from(), but here I confined myself to changing uses of list_second_cell(). Also, fix for_each_cell_setup() and for_both_cell_setup() to const-ify their arguments; that's a simple oversight in 1cff1b95a. Back-patch into v13, on the grounds that (1) the const-ification is a minor bug fix, and (2) it's better for back-patching purposes if we only have two ways to write these loops rather than three. In HEAD, also remove list_third_cell() and list_fourth_cell(), which were also introduced in 1cff1b95a, and are unused as of cc99baa43. It seems unlikely that any third-party code would have started to use them already; anyone who has can be directed to list_nth_cell instead. Discussion: https://postgr.es/m/CAApHDvpo1zj9KhEpU2cCRZfSM3Q6XGdhzuAS2v79PH7WJBkYVA@mail.gmail.com
2020-09-21Copy editing: fix a bunch of misspellings and poor wording.Tom Lane
99% of this is docs, but also a couple of comments. No code changes. Justin Pryzby Discussion: https://postgr.es/m/20200919175804.GE30557@telsasoft.com
2020-09-14Message fixes and style improvementsPeter Eisentraut
2020-08-15Prevent concurrent SimpleLruTruncate() for any given SLRU.Noah Misch
The SimpleLruTruncate() header comment states the new coding rule. To achieve this, add locktype "frozenid" and two LWLocks. This closes a rare opportunity for data loss, which manifested as "apparent wraparound" or "could not access status of transaction" errors. Data loss is more likely in pg_multixact, due to released branches' thin margin between multiStopLimit and multiWrapLimit. If a user's physical replication primary logged ": apparent wraparound" messages, the user should rebuild standbys of that primary regardless of symptoms. At less risk is a cluster having emitted "not accepting commands" errors or "must be vacuumed" warnings at some point. One can test a cluster for this data loss by running VACUUM FREEZE in every database. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20190218073103.GA1434723@rfd.leadboat.com
2020-07-31Fix recently-introduced performance problem in ts_headline().Tom Lane
The new hlCover() algorithm that I introduced in commit c9b0c678d turns out to potentially take O(N^2) or worse time on long documents, if there are many occurrences of individual query words but few or no substrings that actually satisfy the query. (One way to hit this behavior is with a "common_word & rare_word" type of query.) This seems unavoidable given the original goal of checking every substring of the document, so we have to back off that idea. Fortunately, it seems unlikely that anyone would really want headlines spanning all of a long document, so we can avoid the worse-than-linear behavior by imposing a maximum length of substring that we'll consider. For now, just hard-wire that maximum length as a multiple of max_words times max_fragments. Perhaps at some point somebody will argue for exposing it as a ts_headline parameter, but I'm hesitant to make such a feature addition in a back-patched bug fix. I also noted that the hlFirstIndex() function I'd added in that commit was unnecessarily stupid: it really only needs to check whether a HeadlineWordEntry's item pointer is null or not. This wouldn't make all that much difference in typical cases with queries having just a few terms, but a cycle shaved is a cycle earned. In addition, add a CHECK_FOR_INTERRUPTS call in TS_execute_recurse. This ensures that hlCover's loop is cancellable if it manages to take a long time, and it may protect some other TS_execute callers as well. Back-patch to 9.6 as the previous commit was. I also chose to add the CHECK_FOR_INTERRUPTS call to 9.5. The old hlCover() algorithm seems to avoid the O(N^2) behavior, at least on the test case I tried, but nonetheless it's not very quick on a long document. Per report from Stephen Frost. Discussion: https://postgr.es/m/20200724160535.GW12375@tamriel.snowman.net
2020-07-29Add hash_mem_multiplier GUC.Peter Geoghegan
Add a GUC that acts as a multiplier on work_mem. It gets applied when sizing executor node hash tables that were previously size constrained using work_mem alone. The new GUC can be used to preferentially give hash-based nodes more memory than the generic work_mem limit. It is intended to enable admin tuning of the executor's memory usage. Overall system throughput and system responsiveness can be improved by giving hash-based executor nodes more memory (especially over sort-based alternatives, which are often much less sensitive to being memory constrained). The default value for hash_mem_multiplier is 1.0, which is also the minimum valid value. This means that hash-based nodes continue to apply work_mem in the traditional way by default. hash_mem_multiplier is generally useful. However, it is being added now due to concerns about hash aggregate performance stability for users that upgrade to Postgres 13 (which added disk-based hash aggregation in commit 1f39bce0). While the old hash aggregate behavior risked out-of-memory errors, it is nevertheless likely that many users actually benefited. Hash agg's previous indifference to work_mem during query execution was not just faster; it also accidentally made aggregation resilient to grouping estimate problems (at least in cases where this didn't create destabilizing memory pressure). hash_mem_multiplier can provide a certain kind of continuity with the behavior of Postgres 12 hash aggregates in cases where the planner incorrectly estimates that all groups (plus related allocations) will fit in work_mem/hash_mem. This seems necessary because hash-based aggregation is usually much slower when only a small fraction of all groups can fit. Even when it isn't possible to totally avoid hash aggregates that spill, giving hash aggregation more memory will reliably improve performance (the same cannot be said for external sort operations, which appear to be almost unaffected by memory availability provided it's at least possible to get a single merge pass). The PostgreSQL 13 release notes should advise users that increasing hash_mem_multiplier can help with performance regressions associated with hash aggregation. That can be taken care of by a later commit. Author: Peter Geoghegan Reviewed-By: Álvaro Herrera, Jeff Davis Discussion: https://postgr.es/m/20200625203629.7m6yvut7eqblgmfo@alap3.anarazel.de Discussion: https://postgr.es/m/CAH2-WzmD%2Bi1pG6rc1%2BCjc4V6EaFJ_qSuKCCHVnH%3DoruqD-zqow%40mail.gmail.com Backpatch: 13-, where disk-based hash aggregation was introduced.
2020-07-26Tweak behavior of pg_stat_activity.leader_pidMichael Paquier
The initial implementation of leader_pid in pg_stat_activity added by b025f32 took the approach to strictly print what a PGPROC entry includes. In short, if a backend has been involved in parallel query at least once, leader_pid would remain set as long as the backend is alive. For a parallel group leader, this means that the field would always be set after it participated at least once in parallel query, and after more discussions this could be confusing if using for example a connection pooler. This commit changes the data printed so as leader_pid becomes always NULL for a parallel group leader, showing up a non-NULL value only for the parallel workers, and actually as long as a parallel query is running as workers are shut down once the query has completed. This does not change the definition of any catalog, so no catalog bump is needed. Per discussion with Justin Pryzby, Álvaro Herrera, Julien Rouhaud and me. Discussion: https://postgr.es/m/20200721035145.GB17300@paquier.xyz Backpatch-through: 13
2020-07-24Replace TS_execute's TS_EXEC_CALC_NOT flag with TS_EXEC_SKIP_NOT.Tom Lane
It's fairly silly that ignoring NOT subexpressions is TS_execute's default behavior. It's wrong on its face and it encourages errors of omission. Moreover, the only two remaining callers that aren't specifying CALC_NOT are in ts_headline calculations, and it's very arguable that those are bugs: if you've specified "!foo" in your query, why would you want to get a headline that includes "foo"? Hence, rip that out and change the default behavior to be to calculate NOT accurately. As a concession to the slim chance that there is still somebody somewhere who needs the incorrect behavior, provide a new SKIP_NOT flag to explicitly request that. Back-patch into v13, mainly because it seems better to change this at the same time as the previous commit's rejiggering of TS_execute related APIs. Any outside callers affected by this change are probably also affected by that one. Discussion: https://postgr.es/m/CALT9ZEE-aLotzBg-pOp2GFTesGWVYzXA3=mZKzRDa_OKnLF7Mg@mail.gmail.com
2020-07-24Fix assorted bugs by changing TS_execute's callback API to ternary logic.Tom Lane
Text search sometimes failed to find valid matches, for instance '!crew:A'::tsquery might fail to locate 'crew:1B'::tsvector during an index search. The root of the issue is that TS_execute's callback functions were not changed to use ternary (yes/no/maybe) reporting when we made the search logic itself do so. It's somewhat annoying to break that API, but on the other hand we now see that any code using plain boolean logic is almost certainly broken since the addition of phrase search. There seem to be very few outside callers of this code anyway, so we'll just break them intentionally to get them to adapt. This allows removal of tsginidx.c's private re-implementation of TS_execute, since that's now entirely duplicative. It's also no longer necessary to avoid use of CALC_NOT in tsgistidx.c, since the underlying callbacks can now do something reasonable. Back-patch into v13. We can't change this in stable branches, but it seems not quite too late to fix it in v13. Tom Lane and Pavel Borisov Discussion: https://postgr.es/m/CALT9ZEE-aLotzBg-pOp2GFTesGWVYzXA3=mZKzRDa_OKnLF7Mg@mail.gmail.com
2020-07-21neqjoinsel must now pass through collation to eqjoinsel.Tom Lane
Since commit 044c99bc5, eqjoinsel passes the passed-in collation to any operators it invokes. However, neqjoinsel failed to pass on whatever collation it got, so that if we invoked a collation-dependent operator via that code path, we'd get "could not determine which collation to use for string comparison" or the like. Per report from Justin Pryzby. Back-patch to v12, like the previous commit. Discussion: https://postgr.es/m/20200721191606.GL5748@telsasoft.com
2020-07-17Fix whitespacePeter Eisentraut
2020-07-11Forbid numeric NaN in jsonpathAlexander Korotkov
SQL standard doesn't define numeric Inf or NaN values. It appears even more ridiculous to support then in jsonpath assuming JSON doesn't support these values as well. This commit forbids returning NaN from .double(), which was previously allowed. NaN can't be result of inner-jsonpath computation over non-NaNs. So, we can not expect NaN in the jsonpath output. Reported-by: Tom Lane Discussion: https://postgr.es/m/203949.1591879542%40sss.pgh.pa.us Author: Alexander Korotkov Reviewed-by: Tom Lane Backpatch-through: 12
2020-07-11Improve error reporting for jsonpath .double() methodAlexander Korotkov
When jsonpath .double() method detects that numeric or string can't be converted to double precision, it throws an error. This commit makes these errors explicitly express the reason of failure. Discussion: https://postgr.es/m/CAPpHfdtqJtiSXkP7tOXez18NxhLUH_-75bL8%3DOce4Ki%2Bbv7V6Q%40mail.gmail.com Author: Alexander Korotkov Reviewed-by: Tom Lane Backpatch-through: 12
2020-07-09Fix pg_current_logfile() to not emit a carriage return on Windows.Tom Lane
Due to not having our signals straight about CRLF vs. LF line termination, the output of pg_current_logfile() included a trailing \r on Windows. To fix, force the file descriptor it uses into text mode. While here, move a couple of local variable declarations to make the function's logic clearer. In v12 and v13, also back-patch the test added by 1c4e88e2f so that this function has some test coverage. However, the 004_logrotate.pl test script doesn't exist before v12, and it didn't seem worth adding to older branches just for this. Per report from Thomas Kellerer. Back-patch to v10 where this function was added. Discussion: https://postgr.es/m/412ae8da-76bb-640f-039a-f3513499e53d@gmx.net
2020-07-04Fix "ignoring return value" complaints from commit 96d1f423f9Joe Conway
The cfbot and some BF animals are complaining about the previous read_binary_file commit because of ignoring return value of ‘fread’. So let's make everyone happy by testing the return value even though not strictly needed. Reported by Justin Pryzby, and suggested patch by Tom Lane. Backpatched to v11 same as the previous commit. Reported-By: Justin Pryzby Reviewed-By: Tom Lane Discussion: https://postgr.es/m/flat/969b8d82-5bb2-5fa8-4eb1-f0e685c5d736%40joeconway.com Backpatch-through: 11